The present inventions relate to the fabrication and placement of materials at known locations on a substrate. In particular, one embodiment of the invention provides a method and associated apparatus for packaging a substrate having diverse sequences at known locations on its surface.
Techniques for forming sequences on a substrate are known. For example, the sequences may be formed according to the pioneering techniques disclosed in U.S. Pat. No.5,143,854 (Pirrung et. al.), PCT WO 92/10092, or U.S. application Ser. No. 08/249,188 filed May 24, 1994, incorporated herein by reference for all purposes. The prepared substrates will have a wide range of applications. For example, the substrates may be used for understanding the structure-activity relationship between different materials or determining the sequence of an unknown material. The sequence of such unknown material may be determined by, for example, a process known as sequencing by hybridization. In one method of sequencing by hybridization, a sequences of diverse materials are formed at known locations on the surface of a substrate. A solution containing one or more targets to be sequenced is applied to the surface of the substrate. The targets will bind or hybridize with only complementary sequences on the substrate.
The locations at which hybridization occurs can be detected with appropriate detection systems by labeling the targets with a fluorescent dye, radioactive isotope, enzyme, or other marker. Exemplary systems are described in U.S. Pat. No. 5,143,854 (Pirrung et al.) and U.S. patent application Ser. No. 08/143,312, also incorporated herein by reference for all purposes. Information regarding target sequences can be extracted from the data obtained by such detection systems.
By combining various available technologies, such as photolithography and fabrication techniques, substantial progress has been made in the fabrication and placement of diverse materials on a substrate. For example, thousands of different sequences may be fabricated on a single substrate of about 1.28 cm.sup.2 in only a small fraction of the time required by conventional methods. Such improvements make these substrates practical for use in various applications, such as biomedical research, clinical diagnostics, and other industrial markets, as well as the emerging field of genomics, which focuses on determining the relationship between genetic sequences and human physiology.
As commercialization of such substrates becomes widespread, an economically feasible and high-throughput device and method for packaging the substrates are desired.